package com.test.concurrency;

import java.util.Random;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;

class Toast {
	public enum Status {
		DRY, BUTTERED, JAMMED
	}

	private Status status = Status.DRY;
	private final int id;

	public Toast(int idn) {
		id = idn;
	}

	public void butter() {
		status = Status.BUTTERED;
	}

	public void jam() {
		status = Status.JAMMED;
	}

	public Status getStatus() {
		return status;
	}

	public int getId() {
		return id;
	}

	public String toString() {
		return "Toast " + id + ": " + status;
	}
}

class ToastQueue extends LinkedBlockingQueue<Toast> {
}

class Toaster implements Runnable {
	private ToastQueue toastQueue;
	private int count = 0;
	private Random rand = new Random(47);

	public Toaster(ToastQueue tq) {
		toastQueue = tq;
	}

	@Override
	public void run() {
		try {
			while (!Thread.interrupted()) {
				TimeUnit.MILLISECONDS.sleep(100 + rand.nextInt(500));
				// make toast
				Toast t = new Toast(count++);
				System.out.println(t);
				// insert into queue
				toastQueue.put(t);
			}
		} catch (Exception e) {
			System.out.println("Toaster interrupted");
		}
		System.out.println("Toaster off");
	}

}

// apply butter to toast:
class Butterer implements Runnable {
	private ToastQueue dryQueue, butteredQueue;

	public Butterer(ToastQueue dry, ToastQueue buttered) {
		dryQueue = dry;
		butteredQueue = buttered;
	}

	@Override
	public void run() {
		try {
			while (!Thread.interrupted()) {
				// blocks until next piece of toast is available:
				Toast t = dryQueue.take();
				t.butter();
				System.out.println(t);
				butteredQueue.put(t);
			}
		} catch (Exception e) {
			// TODO: handle exception
		}

	}

}

// Apply jam to buttered toast:
class Jammer implements Runnable {
	private ToastQueue butteredQueue, finishedQueue;

	public Jammer(ToastQueue buttered, ToastQueue finished) {
		butteredQueue = buttered;
		finishedQueue = finished;
	}

	@Override
	public void run() {
		try {
			while (!Thread.interrupted()) {
				// block until next piece of toast is available:
				Toast t = butteredQueue.take();
				t.jam();
				System.out.println(t);
				finishedQueue.put(t);
			}
		} catch (Exception e) {
			System.out.println("Jammer interrupted");
		}
		System.out.println("Jammer off");
	}

}

// Consume the toast
class Eater implements Runnable {
	private ToastQueue finishedQueue;
	private int counter = 0;

	public Eater(ToastQueue finished) {
		finishedQueue = finished;
	}

	@Override
	public void run() {
		try {
			while (!Thread.interrupted()) {
				// blocks until next piece of toast is available:
				Toast t = finishedQueue.take();
				// verify that the toast is coming in order,and that all pieces
				// are getting jammed:
				if (t.getId() != counter++
						|| t.getStatus() != Toast.Status.JAMMED) {
					System.out.println(">>>> Error: " + t);
					System.exit(1);
				} else {
					System.out.println("Chomp! " + t);
				}
			}
		} catch (Exception e) {
			System.out.println("Eater interrupted");
		}
		System.out.println("Eater off");
	}

}
/***
 * using BlockingQueue to control Thread 
 * @author Administrator
 *
 */
public class ToastOMatic {
	public static void main(String[] args) throws Exception {
		ToastQueue dryQueue = new ToastQueue();
		ToastQueue butteredQueue = new ToastQueue();
		ToastQueue finishedQueue = new ToastQueue();
		ExecutorService exec = Executors.newCachedThreadPool();
		exec.execute(new Toaster(dryQueue));
		exec.execute(new Butterer(dryQueue, butteredQueue));
		exec.execute(new Jammer(butteredQueue, finishedQueue));
		exec.execute(new Eater(finishedQueue));
		TimeUnit.SECONDS.sleep(5);
		exec.shutdownNow();
	}
}
